Piston



April 12, 1932. A. DRI'EYFUSS PISTON Filed Feb. 28, 1950 2 Sheets-Shet April 12, 1932. A. DREYFUSS PISTON Filed Feb. 28, 1930 2 Sheets-Sheet FIGI I FIG 6- Patented Apr. 12, 1932 UNITED STATES ACHILLE DREYFUSS, OF PARIS, FRANCE PISTON Application filed February 28, 1930, Serial No. 432,139, and in France March 11, 1929.

The object of the present invention is a piston intended more particularly to be utilized in machines such as certain high speed internal. combustion engines.

Pistons are already known in which the gudgeon pin is located in bosses arranged in ribs solid with the piston head, and in which the said bosses are independent of a trunk Connected elastically with the piston head.

The piston according to the present invention is characterized substantially in'that two parallel ribs carrying the bosses which receive the axes of joint are rigidly fixed both to the piston head and to the vertical part which is solid with the said head and which carries the ordinary packing rings. It

is in addition characterized in that the trunk is constituted by a single segment fixed to the said vertical part and that this trunk is provided with twoopenings allowing the said bosses to pass through with considerable play, the bosses being prolonged till flush with the outer surface of the piston body.

Another feature of the invention consists in ensuring the elasticity of the trunk, not

by means of slightly inclined slits, dividing the trunk into several segments, but by a single slit, situated in the plane of the axis of the joint, this slit opening into one of the spaces arranged in the body round the bosses and being continued by a practically parallel slit, which connects the said space with a horizontal slit provided between the trunk and the vertical part of the piston head. Finally, the invention also admits of details or modifications which will be clear from the following description referring to the accompanying drawings, wherein:

Figure 1 shows very diagrammatically a piston according to the invention viewed in vertical section in a plane passing through the axis of the joint of the said piston with the connecting rod which it is to receive.

Figures 2 to 4 also show diagrammatically, respectively, an elevation perpendicular to that of Figure 1, a horizontal section along IH-III in Figure 1 and a view from below.

Figure 5 is a modification in horizontal 60 section along VV of Figure 6, and

Figure 6 is a section alongVL-VI of Figure 5.

The piston comprises a head 1, with whic are made in one piece the other elements enumerated hereafter. A vertical part 2, serving for th reception of the usual packing rings 3 is rigidly connected to the head 1. This cupola 12'is extended downwards in a trunk 4. Two ribs 5, as shown cl-early in Figure 5, are rigidly fixed to the inner face 61 of the head 1 and of the vertical part 2, and these ribs are prolonged in lateral, co-axial expansions or bosses 6, extending diametri- I 'oally towards the periphery of the piston in question, the said bosses being intended to 65 receive gudgeonpins, not shown. As will be seen from Figure 1, these bosses 6 are prolonged till flush with the outer surface of the skirt 4, which substantially increases the bearing surface of the joints, and a space, with considerable play, is provided round the said bosses by means of circular openings 7 drilled in the-trunk 4.

The latter is split at 8 in a. plane substantially parallel to the axis of joint of the piston, either vertically or preferably obliquely as shown in Figure 2. The slit 8 opens into the opening or circular space 7, and extends upwards at 8 as a parallel slit connecting. v the opening 7 and a slit 9 provided between the trunk 4: and the vertical part 2 of the head. 10 are the usual holes for the oil return, forming a communication between the wiper ring groove with the interior of the piston. As shown in the drawing (Figure 1), the suspension of the bosses 6 from the cupola 12 is reinforced by ribs 11, which are attached to the vertical part 2 alone.

It has also been found that it is preferable to form a sort of isolation under the head of 9 the said head from the bosses 6 receiving the axis of the piston, or in other words that it is preferable to reduce as much as possible the mass of material connecting these bosses with the head. For this purpose, the ribs 5 are pro- Finally, a groove 13, intended for the reception of an elastic ring 14:, of tempered steel, for example, may be made in the interior of the trunk 4, if the thickness of the said trunk permits of this, and if not, in a rib 12 provided for the purpose. This ring, keeping' intact, so to speak, its elasticity, irrespective of the heating of the piston or of the medium in which it moves, theyariations in elasticity of the trunk are without efiect on the adjustment of the piston within its cylinder, moreover, this adjustment also remains constant, despite of the relative wear of the said piston and of the said cylinder.

Preferably, a second groove 16 is made in the interior of the trunk 4, for example in a rib 15 provided for this purpose, in which groove also is placed an elastic ring 17, of tempered steel for example, the action of which is added to that of the above-mentioned ring 14.

I claim:

A piston for engines, comprising a head; a vertical cylindrical part solid with this head and carrying the ordinary packing rings; two parallel ribs fixed rigidly to the head and to the said cylindrical part; bosses arranged in each of the said ribs for receiving the gudgeon pin; a trunk constituted by a single segment fixed to the said vertical cylindrical part; holes arranged in this trunk for the passage, with considerable play, of the said bosses; a slit in the said trunk and opening into one of the said holes; a second slit opening also into the same hole a third slit opening into the opposite boss hole; oil holes on the upper periphery of the trunk; several of these oil holes connected in a slit in communication with the second and third slits.

In testimony whereof I have signed this specification.

ACHILLE DREYFUSS. 

